Transport properties of poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate)

The conductivity and magnetoresistance of poly( 3,4-ethylenedioxythiophene)/poly(styrenesulfonate) (PEDT/PSS) have been studied as a function of temperature. The room-temperature conductivities are dependent on the pH of the solutions from which the films are cast; values as high as 20 S/cm can be obtained in films cast from solutions with pH values in the range 0-3, The temperature dependence of the electrical conductivity is characteristic of granular metals (strongly disordered inhomogeneous systems), sigma(T) = sigma(0) exp[-(T-0/T)(1/2)]. The low-temperature magnetoresistance of PEDT/PSS is positive and follows an H-2 dependence at low magnetic fields. (C) 1998 Elsevier Science S.A. All rights reserved.